Method for Generating a Signed Electronic Document with an Anti-Tamper Function

ABSTRACT

A method is to be implemented by a network server, and includes: receiving input information associated with a handwritten signature inputted on an original document, and a dynamic image associated with a motion of a signer during input of the handwritten signature; compiling a signed document based on the original document, the input information and the dynamic image; generating an authentication value based on a location where the handwritten signature is rendered on the signed document and a location where the dynamic image is rendered on the signed document; and incorporating the authentication value into the signed document to result in an anti-tamper document.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority of Taiwanese Invention PatentApplication No. 105133201, filed on Oct. 14, 2016.

FIELD

The disclosure relates to a method for generating a signed electronicdocument, and more particularly to a method for generating a signedelectronic document with an anti-tamper function.

BACKGROUND

A conventional method for generating an electronic signature isdisclosed in U.S. Patent Application Publication No. 2015012812. Theconventional method includes receiving a representative signal ofhandwritten signature inputted by a signer and a dynamic image thatpresents a motion of the signer during signing of the handwrittensignature captured by a dynamic image capturing module as thehandwritten signature is being inputted, and compiling a data file thatincludes the representative signal and the dynamic image to be used insubsequent verification of whether the resultant electronic signature isactually made by the genuine signer. However, the electronic signaturegenerated by the conventional method can only be used to verify theauthenticity of a signature, and cannot prevent a situation where anelectronic document embedded with the conventional electronic signatureis tampered with in a manner that only content therein, for example acheck mark of a checkbox, is altered while the electronic signatureremains untouched.

SUMMARY

Therefore, an object of the disclosure is to provide a method forgenerating a signed electronic document with an anti-tamper functionthat can alleviate at least one of the drawbacks of the prior art.

According to the disclosure, the method is to be implemented by anetwork server communicable with an electronic device. The electronicdevice includes a touch screen and an image capturing module. Theelectronic device executes an application program to load an originaldocument and to display the original document on the touch screen. Themethod includes:

receiving, by the network server from the electronic device, inputinformation that is associated with a handwritten signature inputted bya signer via the touch screen, and a dynamic image that is captured bythe image capturing module and that is associated with a motion of thesigner during input of the handwritten signature;

compiling, by the network server, a signed document based on theoriginal document, the input information and the dynamic image;

generating, by the network server, an authentication value based on alocation where the handwritten signature is rendered on the signeddocument and a location where the dynamic image is rendered on thesigned document; and

incorporating, by the network server, the authentication value into thesigned document to result in an anti-tamper document.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the disclosure will become apparent inthe following detailed description of the embodiment with reference tothe accompanying drawings, of which:

FIG. 1 is a schematic diagram illustrating an embodiment of a networkserver that is communicable with at least one electronic device and thatimplements a method for generating a signed electronic document with ananti-tamper function according to the disclosure;

FIG. 2 is a block diagram illustrating the embodiment of the networkserver that is communicable with an electronic device;

FIG. 3 is a schematic view illustrating an embodiment of an originaldocument displayed on a touch screen according to this disclosure;

FIG. 4 is a flow chart illustrating an embodiment of the method forgenerating a signed electronic document with an anti-tamper functionaccording to this disclosure; and

FIG. 5 is a schematic view illustrating an embodiment of a signeddocument displayed on the touch screen according to this disclosure.

DETAILED DESCRIPTION

FIGS. 1 and 2 illustrate an embodiment of a network server 1 that iscommunicable with an electronic device and that is utilized to implementa method for generating a signed electronic document with an anti-tamperfunction according to this disclosure. The electronic device 2 may beimplemented by a personal computer (PC), a personal digital assistant(PDA), a smartphone, or the like, but is not limited thereto.

The electronic device 2 includes a touch screen 21, an image capturingmodule 22 to face a user of the electronic device 2 (e.g., a signer), aGlobal Positioning System (GPS) receiver 23, and a microphone (notshown). In this embodiment, the image capturing module 22 is implementedby a camera, but implementation thereof is not limited thereto. The GPSreceiver 23 is adapted to receive a GPS signal and to calculate acoordinate set (L) of a position of the electronic device 2. Thecoordinate set (L) may for example include a latitude coordinate and alongitude coordinate.

Referring to FIGS. 1 to 5, an embodiment of the method for generatingthe signed electronic document with the anti-tamper function accordingto this disclosure is illustrated. The method includes steps S31 to S37shown in FIG. 4.

In step S31, the network server 1 provides an application program to theelectronic device 2 for installation of the application program on theelectronic device 2. The electronic device 2 executes the applicationprogram to load an original document (P) and to display the originaldocument (P) on the touch screen 21. In this embodiment, the originaldocument (P) includes a signature area (P1), at least one checkbox (P2)and a predetermined area (P3) as shown in FIG. 3.

In step S32, the network server 1 receives from the electronic device 2the coordinate set (L) calculated by the GPS receiver 23 based on theGPS signal.

In step S33, the network server 1 receives from the electronic device 2,input information (M) that includes information of a handwrittensignature 41 inputted in the signature area (P1) by the signer via thetouch screen 21 and one or more check marks 42 inputted in said at leastone checkbox (P2) via the touch screen 21, and a dynamic image (V) thatis captured by the image capturing module 22 and that is associated witha motion of the signer, such as facial expression and/or movement of asigning hand of the signer, during input of the handwritten signature41. In addition, in one embodiment, the network server 1 also receives,from the electronic device 2, a voice signal that is inputted by thesigner via the microphone of the electronic device 2 and that isassociated with a record of the signer's voice during input of thehandwritten signature 41.

In this embodiment, the handwritten signature 41 and the check mark(s)42 are described by a markup language (such as an extensible markuplanguage, XML). In one embodiment, the handwritten signature 41 may beimplemented by scalable vector graphics (SVG) containing XML syntax.Specifically speaking, the input information (M) may be implemented byrecords of coordinates of positions on the touch screen 21 correspondingto successive touch events on the touch screen 21 that are associatedwith input of the handwritten signature and the check mark(s) 42 by thesigner on the touch screen 21 and that cooperatively constitute amovement of the signing action performed by the singer. In thisembodiment, the dynamic image (V) is implemented by streaming media andstored in a format supporting at least one of standards, such as FlashVideo (with a filename extension .flv or .f4v), H.263, H.264 (with afilename extension .mp4), RealMedia (with a filename extension .rm),Windows Media Video (with a filename extension .wmv), MPEG-4 (with afilename extension .m4v), QuickTime File Format (with a filenameextension .mov), and the like, but is not limited thereto.

In step S34, the network server 1 compiles a signed document (P′) asshown in FIG. 5 based on the original document (P), the inputinformation (M), the dynamic image (V) and the voice signal, such thatthe signed document (P′) includes contents of the original document (P)with a reproduction of the handwritten signature 41 presented in thesignature area (P1) of the signed document (P′), and a reproduction ofthe check mark(s) 42 presented on said at least one checkbox (P2)thereof. Moreover, the network server 1 embeds the dynamic image (V),which is overlaid with another reproduction of the handwritten signature(41) of the input information (M), in the predetermined area (P3) of thesigned document (P′).

In step S35, the network server 1 generates an authentication valuebased on the coordinate set (L), a location where the handwrittensignature 41 is rendered on the signed document (P′) (i.e., thesignature area (P1) in this embodiment), a location where the dynamicimage (V) is rendered on the signed document (P′) (i.e., thepredetermined area (P3) in this embodiment), and a location of eachcheck mark 42 on said at least one checkbox (P2) of the signed document(P′). Thereafter, the network server 1 incorporates the authenticationvalue into the signed document (P′) to result in an anti-tamperdocument. In this embodiment, the authentication value is implemented tobe a Hash value calculated by irreversible Hashing algorithms, butimplementation of the authentication value is not limited thereto.Therefore, the authentication value may vary when at least one of thecoordinate set (L), the location where the handwritten signature 41 isrendered on the signed document (P′), the location where the dynamicimage (V) is rendered on the signed document (P′), or the location ofeach check mark 42 on said at least one checkbox (P2) is altered.

In step S36, the network server 1 requests a timestamp from a TimeStamping Authority (TSA) and incorporates the timestamp obtained fromthe ISA into the anti-tamper document. As a result, creation of theanti-tamper document at a specific time point can be verified by the ISAbased on the timestamp incorporated in the anti-tamper document.Therefore, once the time the anti-tamper document was last modified doesnot correspond to the timestamp, it can be determined that the contentsin the anti-tamper document may have been altered.

In step S37, the network server 1 transmits the anti-tamper document tothe electronic device 2 to enable the electronic device 2 to display,via the touch screen 21, the anti-tamper document which includes thehandwritten signature 41, the check mark 42 and the dynamic image (V).

It should be noted that the order of execution of steps S35 and S36 canbe exchanged. That is to say, the network server 1 may first request thetimestamp from the TSA, and then incorporate the timestamp obtained fromthe TSA into the signed document (P′), followed by generating theauthentication value and incorporating the authentication value into thesigned document (P′) which has been incorporated with the timestamp soas to result in the anti-tamper document (P″). Since implementation ofauthentication of an electronic document by the authentication value iswell known to one skilled in the relevant art, detailed explanation ofthe same is omitted herein for the sake of brevity.

In other embodiments, if no check mark is inputted in said at least onecheckbox (P2) by the signer, the authentication value contained in theanti-tamper document will not be associated with any check mark. In thisway, if the anti-tamper document is tampered with by adding a check mark42 into said at least one checkbox (P2), the authentication value mayserve the purpose of verifying that the content of the anti-tamperdocument has been altered.

In summary, the method of this disclosure includes embedding the dynamicimage (V) overlaid with the reproduction of the handwritten signature 41in the signed document (P′), and generating the authentication valuebased on the coordinate set (L), the location where the handwrittensignature 41 is rendered on the signed document (P′), the location wherethe dynamic image (V) is rendered on the signed document (P′), and thelocation of each check mark 42 on said at least one checkbox (P2), so asto realize the functions of authentication and anti-tampering. Moreover,the method of this disclosure includes incorporating the timestampobtained from the TSA into the anti-tamper document (P″), so as tofacilitate verification of the time when the anti-tamper document iscreated. In this way, the anti-tamper function may be further improved.

In the description above, for the purposes of explanation, numerousspecific details have been set forth in order to provide a thoroughunderstanding of the embodiment. It will be apparent, however, to oneskilled in the art, that one or more other embodiments maybe practicedwithout some of these specific details. It should also be appreciatedthat reference throughout this specification to “one embodiment,” “anembodiment,” an embodiment with an indication of an ordinal number andso forth means that a particular feature, structure, or characteristicmay be included in the practice of the disclosure. It should be furtherappreciated that in the description, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure and aiding in theunderstanding of various inventive aspects.

While the disclosure has been described in connection with what isconsidered the exemplary embodiment, it is understood that thisdisclosure is not limited to the disclosed embodiment but is intended tocover various arrangements included within the spirit and scope of thebroadest interpretation so as to encompass all such modifications andequivalent arrangements.

What is claimed is:
 1. A method for generating a signed electronicdocument with an anti-tamper function, the method to be implemented by anetwork server communicable with an electronic device, the electronicdevice including a touch screen and an image capturing module, theelectronic device executing an application program to load an originaldocument and to display the original document on the touch screen, saidmethod comprising: receiving, by the network server from the electronicdevice, input information that is associated with a handwrittensignature inputted by a signer on the original document via the touchscreen, and a dynamic image that is captured by the image capturingmodule and that is associated with a motion of the signer during inputof the handwritten signature; compiling, by the network server, a signeddocument based on the original document, the input information and thedynamic image; generating, by the network server, an authenticationvalue based on a location where the handwritten signature is rendered onthe signed document and a location where the dynamic image is renderedon the signed document; and incorporating, by the network server, theauthentication value into the signed document to result in ananti-tamper document.
 2. The method as claimed in claim 1, wherein thecompiling a signed document includes requesting, by the network server,a timestamp from a Time Stamping Authority (ISA) and incorporating, thenetwork server, the timestamp obtained from the TSA into the signeddocument.
 3. The method as claimed in claim 1, subsequent to theincorporating the authentication value, further comprising: requesting,by the network server, a timestamp from a Time Stamp Authority (ISA) andincorporating, by the network server, the timestamp obtained from theISA into the anti-tamper document.
 4. The method as claimed in claim 1,the original document including a signature area and at least onecheckbox, wherein in the receiving input information, the inputinformation includes information of the handwritten signature inputtedin the signature area and a check mark inputted on said at least onecheckbox via the touch screen.
 5. The method as claimed in claim 4,wherein the generating an authentication value includes generating, bythe network server, the authentication value further based on a locationof the check mark on said at least one checkbox.
 6. The method asclaimed in claim 1, wherein the compiling a signed document includesembedding, by the network server, the dynamic image, which is overlaidwith a reproduction of the handwritten signature of the inputinformation, in a predetermined area of the signed document.
 7. Themethod as claimed in claim 1, further comprising: receiving, by thenetwork server from the electronic device, a coordinate set of aposition of the electronic device; wherein the generating anauthentication value includes generating, by the network server, theauthentication value further based on the coordinate set
 8. The methodas claimed in claim 7, the electronic device further including a GlobalPositioning System (GPS) receiver that is adapted to receive a GPSsignal and to calculate the coordinate set of the position of theelectronic device, wherein the receiving a coordinate set includesreceiving, by the network server from the electronic device, thecoordinate set calculated by the GPS receiver based on the GPS signal.9. The method as claimed in claim 1, further comprising: transmitting,by the network server, the anti-tamper document to the electronic deviceto enable the electronic device to display, via the touch screen, theanti-tamper document which contains the handwritten signature and thedynamic image presented thereon.